Lesson 4 - Classifying Chemical Reactions II

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Title: Classifying Chemical Reactions II

Summary

This lesson will be the second day of classifying chemical reactions. The purpose of this lesson is to expose students to more chemical reactions and to give them more practice. A lot of material was presented in the first lesson on this topic, as we went over all of the reaction types, so the first half of this lesson will be dedicated to practicing classifying reactions and predicting products of reactions. We will also discuss reactions in aqueous solution, complete ionic, and net ionic equations. This lesson also includes a laboratory experiment on double replacement reactions. The purpose of this experiment is to determine how a double replacement reaction can be identified and to predict whether or not the reaction will occur.

Objectives

Students will be able to:
  • identify the 5 basic types of chemical reactions: synthesis, combustion, decomposition, single replacement, and double replacement.
  • classify chemical reactions into the five major categories (synthesis, combustion, decomposition, single replacement, and double replacement).
  • give an example of each type of chemical reaction.
  • describe the characteristics of each type of chemical reaction.
  • predict products of chemical reactions
  • write balanced chemical equations for reactions
  • describe evidence of a double replacement reaction

Materials

Instruction

Opening (10 minutes)

  • When students walk into the classroom, two things will be written on the board: the Chemistry Checkpoint question and the objectives for the days lesson.
  • Chemistry Checkpoint: Predict the products of the following reactions and make sure they are balanced, classify each reaction as S, D, SR, DR:
    • Pb(NO3)2 + K2CrO4 -->
    • Cl2 + NaBr -->
    • CuCl2 -->
  • Once attendance is taken and students have completed their Chemistry Checkpoint question, we will go over the CC and the homework from the previous night. I will have a few students write their answers on the board and we will go over them as a class. This will serve as good review and practice, as well as informal assessment for me to see how students are doing with balancing chemical equations.

Middle (70 minutes)

Activity 1: (25 minutes)
  • I will show students another way to classify chemical reactions: the color method. similar to A + B --> AB, except it uses colors so it is more visual. (this will take ~10 minutes)
  • I will hand out the Classifying Chemical Equations: More Practice! worksheet. Students will be allowed to work together quietly. Students will be given ~15 minutes to work on this assignment.
  • After 15 minutes (or when students are done) we will go over the worksheet. I will call on students to answer the questions for Part I. If there are any discrepancies, I will explain it further using the color method.
Activity 2: (45 minutes)
  • I will pass out the Double Replacement lab to each student. I will go over the safety precautions and give instructions for the experiment. I will briefly go through what students are expected to do and demonstrate how to handle the hydrochloric acid, sodium hydroxide, and barium chloride, as they can be dangerous to work with (corrosive, toxic). Before letting the students get to work, I will make sure they understand what they are required to do and how they are expected to handle the chemicals.
  • Students will break up into their designated partners and begin the experiment.
  • When students get to their lab benches, they will be set up with all the materials they will need. As students begin their experiment, I will walk around the classroom and observe each group. I will be available to help students who have questions, but my primary purpose will be to ask students probing questions that will make them think about each step of the experiment. I will make sure students make a prediction about what they think will happen when they carry out each reaction before they actually mix the reactants. This will help students make sense of what they are doing and why it is important.
  • As I am walking around asking questions and making clarifications, I will be monitoring student progress as formative assessment. I will also be paying close attention to students to make sure they are being safe and responsible with the lab materials, especially the chemicals, as they can be dangerous if they are not used appropriately.
  • Once students complete their lab activity, they will clean up their lab benches and go back to their seats. I will instruct the students who have finished to work quietly at their seats on the analysis and conclusion of their experiment while we wait for the entire class to finish.
  • I will supervise the proper disposal of all materials and make sure students clean up safely.

Closing (10 minutes)

  • I will sum up the lesson by revisiting the day's objectives and summarizing what we learned about the types of chemical reactions and how to identify double replacement reactions.
    • In order to reflect on the class and determine the main point, as a class we will come up with a one-two sentence summary of the class. I will ask the students to write this down each day in order to use it in future classes, as well as to use as a study guide for the unit test.
      • "If you had to summarize the main idea of today's lesson, what would you say? As a class let's come up with a few sentences to summarize what we learned today and why it is important."
  • I will tell students that next class we will be learning about the chemistry involved in fireworks. Their homework will be to finish the Double Replacement lab and to continue working on their Adopt-a-Chemical Reaction project.

Notes